Electrochemical sensor based on multi-walled carbon nanotubes for imidacloprid determination

Area of Science:

• Electrochemistry
• Analytical Chemistry
• Materials Science

Background:

• Imidacloprid (IMI) is a widely used neonicotinoid insecticide.
• Accurate detection of IMI is crucial for environmental and food safety monitoring.
• Existing detection methods may lack sensitivity, selectivity, or simplicity.

Purpose of the Study:

• To develop a simple and robust electrochemical sensor for imidacloprid (IMI) determination.
• To investigate the electrochemical behavior and reduction mechanism of IMI.
• To validate the sensor's performance in complex real-world samples.

Main Methods:

• Fabrication of a glassy carbon electrode (GCE) modified with functionalized multi-walled carbon nanotubes (fMWCNT) and Nafion®.
• Square-wave voltammetry (SWV) was employed for IMI detection.
• Optimization of buffer pH, Nafion® concentration, accumulation potential, and time.

Main Results:

• The sensor exhibited a linear response for IMI in the range of 2.00 × 10⁻⁷ to 1.77 × 10⁻⁶ mol L⁻¹.
• Achieved a low limit of detection (3.74 × 10⁻⁸ mol L⁻¹) and limit of quantification (1.25 × 10⁻⁷ mol L⁻¹).
• Demonstrated excellent repeatability, reproducibility (<5% RSD), and high recovery rates (93-97%) in real samples with minimal interference.

Conclusions:

• The developed fMWCNT-Nafion®/GCE sensor is a simple, robust, and highly sensitive platform for imidacloprid detection.
• The sensor shows excellent selectivity and applicability for analyzing IMI in environmental and food matrices.
• The electrochemical reduction of IMI involves two protons and four electrons, indicating nitro group reduction to hydroxylamine derivatives.